July 27, 2012

Exploding Toxic Termites: Oh Yeah, It’s A Real Thing

Just like wine and scotch, a species of termite has been found to just get better with age, except instead of developing tasty tannins, they develop a bitter way of inflicting pain on their enemies.

As worker termites begin to grow older, their ability to perform their duties starts to age with it. However, instead of moving off to Florida, living off a nest egg and retiring, they develop a toxic crystal backpack and start a new role of defending their colonies.

Researchers reported in the journal Science that many termite species can perform a type of suicide attack known as "autothysis," in which the "soldier" termites "explode" to defend their colonies.

However, with the Neocapritermes taracua termite species, it was found that the older termites have a crystal backpack that releases a toxic chemical that sticks to their intruders, eventually corroding their bodies.

"[Autothysis] is usually a one component system. The defensive secretions are stored in salivary glands, but in these species there is a 'backpack' with two crystals carried outside the body. When the termite bursts, the two mix together, producing the more toxic compounds," Prof Yves Roisin from the Free University of Brussels told BBC News.

As the worker termites in these species grow older, they store up crystals that produce a chemical reaction when mixed with glandular secretions, which increases the toxicity of their explosiveness.

When a worker is attacked, its body wall ruptures, and an internal gland full of the toxic mess gives the elderly insect the last laugh.

During a study of the insects, the researchers noticed that some of the termites they were studying had blue spots at the junction between the thorax and abdomen. The blue spots they found are what they are calling "backpacks."

Just to ensure that it was the blue spots that gave them their power, the biologists transplanted the crystals from blue workers onto the plain white workers. They found that the white workers that had the backpacks installed packed a bigger punch afterwards.

Biologists believe this defense mechanism allows the aging workers to become more "useful" to the colony. They were able to determine which termites were the older in the group by observing their mandibles.

As a termite ages, its mandibles start to wear down after having spent its life chewing on wood. The larger the blue crystals on the termite, the more blunt its mandibles were, according to the researchers.

Scientists are still unsure exactly how the crystals are synthesized, or whether other species in the genus have evolved a similar backpack system.

“It´s difficult to get the pure secretions from inside the body,” Dr. Roisin said in a press release. “We are also trying now to understand how this behavior evolved within this termite species, because there are other related species that don´t explode.”